Saturday, March 13, 2010

Project: POCSAG paging network infrastructure

Like OH2LAK reported on his blog, I've started implementing infrastructure code for an amateur radio paging network. Erik (OH2LAK), Weltto (OH7JEV) and Lasse (OH3HZB) got the POCSAG modem running, interfaced it to a Motorola radio, and configured a couple of pagers to receive it on 144.975 MHz.

I got the bits and pieces yesterday for development and debugging, started working on the server software at 6.30 PM yesterday evening, and now I have a working client-server paging network infrastructure with strong authentication, queuing, and support for multiple transmitters. I grabbed quite a bunch of code from the code base, of course.

The system consists of:
  • A server component which receives messages from authenticated message source clients, queues them, and provides them to the transmitter clients
  • A client library (Perl module) which is used to communicate with the API of the server
  • A transmitter client, which fetches messages from the server using the client library and feeds them to the POCSAG modem (and, optionally, transmits CWID at regular intervals)
  • And, for demonstration purposes, a DX cluster client which maintains a connection to a DX cluster server, filters DX spots, and sends them to the paging server using the client library. I think I've made a full circle now, over the past 15 years. Feels like home.
The next thing I'll write is an APRS-IS client to collect APRS messages from the APRS-IS and gateway the to the paging server (for those recipients who have a pager configured on the server).

The server is designed so that it's possible to run multiple instances of it at diverse network locations, so that losing one server will not break the whole network.

The network will probably be national, within Finland, coordinated by RATS (Radio amateur technology society of Finland). The system will be demonstrated at the RATS technology day in Otaniemi, Espoo, 20th of March, 2010 (that's next Saturday). I suppose the code and documentation will be published so that you can set up your own networks.


rickey winders said...

this is off subject ....
but if found a non-listed AIS receiver, it is in the middle of the US and it tracks the barge traffic on the OHIO river....
KC9HAX (from kc9hax) - info
2007-01-01 22:12:58z - 2010-03-14 05:00:57z
AIS: receiver 147.285+ rpt
Local Rpt 147.285+ and 443.875+
for all of the work you put into this great sight

Anonymous said...

I am making AVR POCSAG encoder by N2RVQ with ATTiny2313. I downloaded
a patch for ATTiny2313, but I have troubles with compiling the firmware. AVRStudio displaying critical error at string:
ld poc_char, X+ ; get char

Can you send me a compiled firmware? My E-mail is

P.S. Sorry for my bad English.

Anonymous said...

PLEEEEEASE post your code for this. I am considering doing something similar here in Central Pennsylvania USA and have not found anything new related to amateur pocsag in a very long time. Thank you in advance!

KB3TZD, Heather

Unknown said...

This has such potential for EmmComm groups. I would also like to try to get it up and running locally. Please post, email or link to the code.

Hessu said...

I finally finished packaging the software last weekend, and documented it a bit here:

Alex said...

Thank you so much for posting your code! I have been eagerly awaiting it!

Unknown said...

Any chance you will publish the client-server code. I am looking at setting up a system here and I would love to learn from your code.


Hessu said...

Matt: The client is already released ( but the server isn't in such shape yet. I'll probably release one later when I'm happy with it. But please don't hold your breath while waiting.

Unknown said...

Is this still alive? For the radio comms unit in Belgium (RCO) we re looking to setup a pocsag system but we are still looking for a good base system (like a server/client) to have it running. Please inform me on


la1mna said...

hey are the opportunity and get info about this.
all links are dead. I am very intrresert in this

E-mail me on